SIZE GUIDE: 25" for 9 to 24 months, 30" for toddler to 5 yrs, 36" for 5 yrs to about 5 ft. tall, 42" for over 5 ft. Actual Measuring Method (recommended when buying for KIDS): Measure the distance from back waistline of pants, diagonally over the shoulder, to front waistline. The next larger size will be your correct length.